# Batch 2017-batch-04 #

4 grains of 29mm using sorbitol, intended to be a reloads for the 
second-longest GMA 29mm snap-ring case.  Grain length 45mm with 1mm spacing 
per grain, so we'll make the casting tubes 46mm long.  Delrin coring rods of 
5/16" diameter.  

Formula for a batch size of 135g:

* 65% KNO3, 87.75g, taken from the big bucket
* 35% Sorbitol, 47.25g
* 1% RIO, 1.35g
* PolyStep B1, 2 drops

Presto Multicooker operated at 275F indicated.

These grains were cast on 1 June 2017.

Simulation says:

<p>
<!--Begin motor 29mm 4-grain Sorbitol #14 HTML export from MotorSim-->
<table class='motor' style='text-align: left; border: 1px solid black'><tr><th colspan='6' class='title'>29mm 4-grain Sorbitol #14</th></tr><tr class='summary'><th>Rating:</th><td>99% G-180</td><th>Max Pressure:</th><td>6.47 MPa (939 psi)</td></tr><tr class='summary'><th>Total Impulse:</th><td>159 Ns</td><th>Specific Impulse:</th><td>133 s</td></tr><tr class='summary'><th>Max Thrust:</th><td>228 N</td><th>Volume Loading:</th><td>69%</td></tr><tr class='summary'><th>Average Thrust:</th><td>180 N</td><th>Fuel Mass:</th><td>122 g</td></tr><tr><td colspan='4' class='thrust'><img src='http://chart.apis.google.com/chart?chxt=x,x,y,y,r,r&chs=400x200&cht=lxy&chco=3072F3&chds=0,0.89,0,227.96&chxr=0,0,0.89|2,0,227.96|4,0,51.25&chd=t:0,0,0,0,0,0,0,0,0,0,0.02,0.04,0.07,0.12,0.19,0.29,0.44,0.52,0.65,0.78,0.8,0.88,0.89|0,10.15,19.94,29.95,39.31,47.83,55.66,62.85,69.45,75.47,134.47,149.05,157.98,170.21,186.92,207.36,225.35,227.96,219.77,198.86,37.95,0.12,0.06&chxl=1:|s|3:|N|5:|lbf&chxp=1,50|3,50|5,50' width='400' height='200' alt='null' /></td></tr></table>
<!--End motor 29mm 4-grain Sorbitol #14-->
</p>

## Results ##

Average casting tube mass 1.25g.

* Grain 1, ?g gross, ?g net
* Grain 2, ?g gross, ?g net
* Grain 3, ?g gross, ?g net
* Grain 4, ?g gross, ?g net

Total of ?g propellant, vs 122g simulated.

With a 7.40" liner, 14/64" nozzle throat, buna-n o-rings, simulation says
this reload will be a 99% G-180, 159 Ns, with about an 0.8 sec burn.